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Family
Poeciliidae
| This
group of live-bearing toothcarps (native to
Central and South America, as well as southern North America) displays
obvious sexual dimorphism. Males are usually much smaller and often
more brightly coloured. Their anal fins are modified into a moveable,
elongated tube (gonopodium) used for transferring packets of sperm
to the female's cloaca for internal fertilisation, an uncommon feature
in the world of fishes. |
Anal fins of male Gambusia
Anal fins of female Gambusia |
The fertilised eggs
continue to develop in the body of the female until the fry hatch and are
discharged into the water (live birth).
Many
species are favourite aquarium fish, being hardy, colourful and easy
to breed. They are widely cultured and bred into numerous artificial
colour varieties to suit the tastes of different aquarists. In this
respect, they are very valuable, forming the essence of the local
aquarium fish industry. Others, however have been deliberately brought
around the world to combat mosquitoes. At least three species have
been introduced and become firmly established in Singapore.
Genus
Poecilia
|
Specially bred guppy
Photo: Tan Bee Hong
Another specially
bred guppy
Photo: Yip Hoi Kee |
Euryhaline; ovoviviparous;
omnivorous; gregarious; pelagic. Typical livebearers which consists of well
known species like guppies and mollies. Although considered freshwater fish,
they are also equally at home in brackish and even full strength marine
water (especially mollies).
Wild
strain of Guppy
Photo: Tan Bee Hong |
Guppy
Poecilia reticulata
Ikan Parit, Mata Lalat, 
3 cm (males),
6 cm (females). Feral, abundant. |
Widespread in water
channels throughout Singapore except in forest streams.
The diminutive but extremely prolific guppy was originally introduced for
mosquito control (probably sometime in the early 1900s), and has since colonised
many of Singapore's disturbed freshwater bodies. It is a very successful
little fish, being able to survive in conditions which few other fishes
can tolerate, e.g., polluted canals and even sewage tanks. They are also
an all time favourite with aquarists, with numerous fancy and colourful
strains having been selectively bred as part of a multi-million dollar industry.
Rejected fish also provide a useful and convenient source for the subsidiary
feeder fish industry. The common name is derived from
the Reverend J L Guppy of Trinidad, who obtained early samples of the fish
in its native land.
Male
Lesser Sailfin Molly
Photo: Yip Hoi Kee |
Lesser
Sailfin Molly
Poecilia latipinna
Ikan Parit, 
10 cm (males),
12 cm (females). Feral, brackish waters. Canals, drains, ponds and
estuarine waters. |
The
Lesser Sailfin Molly is native to Mexico and the southern United States.
The males of this species have sail-like dorsal fins and make attractive
aquarium pets. Many colour varieties have been bred, ranging from
multi-coloured to jet-black.
They tend to thrive better in brackish water. In the aquarium, mollies
seem to be rather prone to fungal infection if kept for long periods
in pure fresh water.
The presence in Singapore of a larger and very similar species, the
Yucatan or Greater Sailfin Molly, Poecilia velifera from Southeastern
Mexico is suspected. Poecilia velifera tends to grow larger,
the males reaching 15 cm and the female 18 cm in length. The dorsal
fin of P. velifera has more fin rays (18 to 19) compared to
P. latippina (13 to 16). |
Sailfin Molly (male)
Photo: Tan Bee Hong
Black Sailfin Molly
Photo: Tan Bee Hong
Golden Molly
Piebald Molly
|
Female Common Molly
Male Common Molly
Photos: Yip Hoi Kee |
Common
Molly
Poecilia sphenops
Ikan Parit, 
12 cm. Feral,
common in brackish water. Rural streams, canals, drains and ponds.
Not as colourful as P. velifera or P. latipinna, but
more common. The males of this species do not possess large, sail-like
dorsal fins. It is mainly used to feed predatory pet fish. |
Genus
Gambusia
Female Mosquito Fish
Male Mosquito Fish
Photos: Yip Hoi Kee |
Mosquito
Fish
Gambusia holbrookii
Ikan Parit, 
Euryhaline; 3
cm (males), 6 cm (females); ovoviviparous; omnivorous; gregarious.
Feral, common. Rural streams, canals, drains and ponds.
Native to southern United States and Mexico, this unassuming little
fish has been brought round the |
world (previously known
as Gambusia affinis) to combat mosquito larvae, hence its name. It
is highly adaptable and prolific. Although seldom kept as an ornamental
fish due to its drab colours, it is collected for the feeder fish industry.
|
Introduction
Freshwater habitats
Fishes in Singapore
Conservation
Amazing Fishy Facts
About the guidebook |
